As is well known to persons skilled in the art, the use of devices operated electronically by a computer, which are capable of actuating such parts and/or capable of controlling some functions depending on the rotation and the angular position of the cylinder with needles has already been established in circular stocking knitting machines. These devices are able to reveal, moment by moment, the angular position of the rotating cylinder and therefore of the needles and to manage the signals that derive from them for carrying out a knitting program stored in the electronic computer for a knitting design, either with continuous rotating motion or with reciprocating rotating motion of the cylinder.
Thus, and for example, a previous Italian Patent No. 1180375 of the same applicant describes a multiple-feed circular stocking knitting machine, which comprises a cylinder with needles that is controlled, either with continuous rotating motion or with reciprocating rotating motion, by a motor apparatus controlled by an electronic computer and capable of providing signals for determining the angular position of the cylinder moment by moment, at least one unit for selecting the needles corresponding to the feed stations of the control cams of the vertical movements of the needles selected at each feed station, and in which each feed unit is electronically controlled for selecting needle by needle either in the forward stroke or return stroke of the reciprocating motion of the cylinder and depending on the signals which indicate the angular position of the rotating cylinder. However, in such an embodiment, it is necessary to protect all the feeds with special cams as the needles that are inactive always pass by high, for which reason it is necessary to prevent their interference with other parts.
A circular stocking knitting machine, still operated electronically and having structure for the manufacture of knitted parts with reciprocating motion, as in the heel or in the toe of a stocking, sock or the like, which structure includes the so-called needle-lifter and needle-lowerer pickers, which are arranged and act in such a manner as to reduce the angle of rotation of the cylinder when it moves with reciprocating motion, was then proposed in a subsequent patent of the same applicant.